The incident was very upsetting to the couple, a spokesman for the family said Friday. He refused to speculate on the motive behind the vandalism.

The couple could not be reached for comment. The house they are building is in a sparsely populated, predominantly white neighborhood.

''They're a nice young couple,'' said the spokesman, who did not wish to be identified. ''For something like this to happen in this day and age.''

T.H. Poole Sr., state and local president of the National Association for the Advancement of Colored People, said the vandalism reflects the fallout from recent U.S. Supreme Court decisions that the NAACP regards as attacks on affirmative action laws.

''The good silent majority needs to speak out condemning this type of act,'' said Poole. ''It's a divisive act. Whether it affects me or anybody else, I need to have some concern about it. . . . Until we all come together, we've got to understand that it's still one nation.''

''I'd like to catch somebody like that and let the law deal with them,'' he said. ''If I catch people destroying other people's property or counterfeiting as Ku Klux Klansmen, I am going to sue them.''

Bastanzio said such acts give his organization a bad name, adding that his members ''know better than'' to try to frighten a black family out of a predominantly white neighborhood.